1. Field of the Invention
The present invention relates generally to the conversion of biomass under high severity to produce high quality bio-oil and byproducts, wherein the byproducts can be recovered and/or processed to provide one or more commercially valuable streams.
2. Description of the Related Art
With the rising costs and environmental concerns associated with fossil fuels, renewable energy sources have become increasingly important. The development of renewable fuel sources provides a means for reducing the dependence on fossil fuels. Accordingly, many different areas of renewable fuel research are currently being explored and developed.
With its low cost and wide availability, biomass has increasingly been emphasized as an ideal feedstock in renewable fuel research. Consequently, many different conversion processes have been developed that use biomass as a feedstock to produce useful biofuels and/or specialty chemicals. Existing biomass conversion processes include, for example, combustion, gasification, slow pyrolysis, fast pyrolysis, liquefaction, and enzymatic conversion. One of the useful products that may be derived from the aforementioned biomass conversion processes is a liquid product commonly referred to as “bio-oil.” Bio-oil may be processed into transportation fuels, hydrocarbon chemicals, and/or specialty chemicals.
Although many of these biomass conversion processes can produce high yields of bio-oil, most, if not all, of the bio-oil produced is of low quality due to the high amounts of oxygen present in the bio-oil. Due to the high amounts of oxygen, these low quality bio-oils require extensive secondary upgrading in order to be utilized as transportation fuels and/or as fuel additives. However, many secondary upgrading processes, such as hydrotreatment, are prohibitively expensive due to the need for excess hydrogen in upgrading the bio-oil. Since hydrogen is not naturally produced during most biomass conversion reactions, it must be acquired through an outside source, thus adding to the costs of upgrading bio-oil.
Accordingly, there is a need for an improved process and system for producing and upgrading bio-oil into renewable fuels and/or fuel additives.